This invention relates to robotically assisted surgery, and more particularly provides surgical tools having improved mechanical and/or data interface capabilities to enhance the safety, accuracy, and speed of minimally invasive and other robotically enhanced surgical procedures.
In robotically assisted surgery, the surgeon typically operates a master controller to remotely control the motion of surgical instruments at the surgical site. The controller may be separated from the patient by a significant distance (e.g., across the operating room, in a different room, or in a completely different building than the patient). Alternatively, a controller may be positioned quite near the patient in the operating room. Regardless, the controller will typically include one or more hand input devices (such as joysticks, exoskeletol gloves, master manipulators, or the like) which are coupled by a servo mechanism to the surgical instrument. More specifically, servo motors move a manipulator or xe2x80x9cslavexe2x80x9d supporting the surgical instrument based on the surgeon""s manipulation of the hand input devices. During an operation, the surgeon may employ, via the robotic surgery system, a variety of surgical instruments such as tissue graspers, needle drivers, electrosurgical cautery probes, etc. Each of these structures performs functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, or dissecting, cauterizing, or coagulating tissue.
This new method of performing robotic surgery has, of course, created many new challenges. One such challenge is that a surgeon will typically employ a significant number of different surgical instruments during each surgical procedure. The number of independent surgical manipulators will often be limited due to space constraints and cost. Additionally, patient trauma can generally be reduced by eliminating the number of tools used at any given time. More specifically, in minimally invasive procedures, the number of entry ports into a patient is generally limited because of space constraints, as well as a desire to avoid unnecessary incisions in the patient. Hence, a number of different surgical instruments will typically be introduced through the same trocar sleeve into the abdomen during, for example, laparoscopic procedures. Likewise, in open surgery, there is typically not enough room adjacent the surgical site to position more than a few surgical manipulators, particularly where each manipulator/tool combination has a relatively large range of motion. As a result, a number of surgical instruments will often be attached and detached from a single instrument holder of a manipulator during an operation.
Published PCT application WO98/25666, filed on Dec. 10, 1997 and assigned to the present assignee (the full disclosure of which is incorporated herein by reference) describes a Multicomponent Telepresence System and Method which significantly improves the safety and speed with which robotic surgical tools can be removed and replaced during a surgical procedure. While this represents a significant advancement of the art, as is often true, still further improvements would be desirable. In particular, each tool change which occurs during a surgical procedure increases the overall surgery time. While still further improvements in the mechanical tool/manipulator interface may help reduce a portion of this tool change time, work in connection with the present invention has shown that the mechanical removal and replacement of the tool may represent only one portion of the total interruption for a tool change. U.S. Pat. No. 5,400,267 describes a memory feature for electrically powered medical equipment, and is also incorporated herein by reference.
As more and more different surgical tools are provided for use with a robotic system, the differences between the tool structures (and the interaction between the tool and the other components of the robotic system) become more pronounced. Many of these surgical tools will have one or more degrees of motion between the surgical end effectors and the proximal interface which engages the tool to the holder of the manipulator. The desired and/or practicable ranges of motion for an electrosurgical scalpel may be significantly different than those of a clip applier, for example. Work in connection with the present invention has found that even after a tool is properly placed on the surgical manipulator, the time involved in reconfiguring the robotic system to take advantage of a different tool, and to perfect the master controller""s effective control over the degrees of motion of the tool, may add significantly to the total tool change delay.
In light of the above, it would be desirable to provide improved robotic surgery tools, systems, and method. It would further be desirable to provide techniques for reducing the total delay associated with each tool change. It would be especially desirable if these enhanced, and often more rapid, robotic tool change techniques resulted in still further improvement in the safety and reliability of these promising surgical systems.
The present invention generally provides improved robotic surgical devices, systems, and methods for preparing for and performing robotic surgery. The robotic tools of the present invention will often make use of a memory structure mounted on a tool, manipulator arm, or movable support structure. The memory can, for example, perform a number of important functions when a tool is loaded on the tool manipulator: first, the memory can provide a signal verifying that the tool is compatible with that particular robotic system. Secondly, the tool memory may identify the tool-type (whether it is a scalpel, needle grasper, jaws, scissors, clip applier, electrocautery blade, or the like) to the robotic system so that the robotic system can reconfigure its programming to take full advantage of the tools"" specialized capabilities. This tool-type data may simply be an identification signal referencing further data in a look-up table of the robotic system. Alternatively, the tool-type signal provided by the tool may define the tool characteristics in sufficient detail to allow reconfiguration of the robotic programming without having to resort to an external table. Thirdly, the memory of the tool may indicate tool-specific information, including (for example) measured calibration offsets indicating misalignment between the tool drive system and the tool end effector elements, tool life data (such as the number of times the tool has been loaded onto a surgical system, the number of surgical procedures performed with the tool, and/or the total time the tools has been used), or the like. The information may be stored in some form of non-volatile memory such as one-time programmable EPROM, Flash EPROM, EEPROM, battery-backed-up SRAM, or similar memory technology where data can be updated and retained in either a serial or random access method, or with any of a wide variety of alternative hardware, firmware, or software. The invention further provides improved engagement structures for coupling robotic surgical tools with manipulator structures.
In a first aspect, the invention provides a robotic surgical tool for use in a robotic surgical system. The robotic surgical system has a processor which directs movement of a tool holder. The tool comprises a probe having a proximal end and a distal end. A surgical end effector is disposed adjacent the distal end of the probe. An interface is disposed adjacent to the proximal end of the probe. The interface can be releasably coupled with the tool holder. Circuitry is mounted on the probe. The circuitry defines a signal for transmitting to the processor so as to indicate compatibility of the tool with the system.
The tool will often comprise a surgical instrument suitable for manipulating tissue, an endoscope or other image capture device, or the like. Preferably, the signal will comprise unique tool identifier data. The processor of the robotic surgical system may include programming to manipulate the tool identifier according to a pre-determined function or algorithm so as to derive verification data. The signal transmitted to the processor will often include the verification data. Alternative compatibility signals may include a signal which is listed in a table accessible to the processor, an arbitrary compatibility data string, or the like.
In another aspect, the invention provides a robotic surgical component for use in a robotic surgical system having a processor and a component holder. The component comprises a component body having an interface mountable to the component holder. The body supports a surgical end effector, and a drive system is coupled to the body for moving the end effector per commands from the processor. Circuitry is mounted on the body and defines a signal for transmitting to the processor. The signal may indicate compatibility of the component with the system, may define a component type of the component, may indicate coupling of the component to the system, and/or may indicate calibration of the component. Typically, the component will comprise a surgical tool, a manipulator arm, a pre-positioning linkage supporting the manipulator arm, or the like.
In another aspect, the invention provides a method for installing a robotic surgical component in a robotic surgical system. The method comprises mounting the component to a component holder. A signal is transmitted from the component to a processor of the robotic surgical system. The component is articulated in response to the signal per commands of the processor.
In many embodiments, compatibility of the component with the robotic surgical system will be verified using the signal transmitted from the component to the processor. This can be accomplished by providing unique identification data on the component, and deriving verification data from the identification data according to an algorithm. The verification data is stored with a memory of the component, the signal transmitted to the processor including both the identification and verification data. The algorithm may then be performed on the transmitted unique identification data with the processor, and the results compared with the verification data. Advantageously, this method can take advantage of unique identification data which is often unalterably stored in a memory of commercially available integrated circuits.
In another aspect, the invention provides a robotic surgical tool for use in robotic surgical systems having a processor. The tool comprises a shaft having a proximal end and a distal end. A surgical end effector is disposed adjacent the distal end of the shaft. The end effector has a plurality of degrees of motion relative to the proximal end. An interface is disposed adjacent the proximal end of the shaft. The interface can be releasably coupled with a robotic probe holder. The interface comprises a plurality of driven elements. A plurality of tool drive systems couple the driven elements to the degrees of motion of the end effector. The tool drive system has calibration offsets between a nominal relative position of the end effector and the driven elements, and a measured relative position of the end effector and driven elements. A memory stores data indicating the offsets. The memory is coupled to the interface so as to transmit the offsets to the processor.
In yet another aspect, the invention provides a robotic surgical system comprising a plurality of tools of different tool-types. Each tool comprises an elongate shaft with a cross-section suitable for introduction into an internal surgical site within a patient body via a minimally invasive opening. A distal surgical end effector is coupled to the shaft by at least one joint. The joint is drivingly coupled to a proximal interface by a tool drive system. Circuitry of the tool transmits a tool-type via the interface. The tool types may optionally differ in at least one characteristic such as joint geometry, end effector geometry, drive system characteristics, end effector or drive system strength, or the like. The system also includes a robotic manipulator including a linkage supporting a tool holder. The tool holder releasably receives the interface. A manipulator drive motor drivingly engages the linkage so as to move the tool holder relative to the opening and position the shaft within the surgical site. A tool drive motor is coupled to the tool holder so as to drivingly engage the tool drive system and articulate the joint. A processor is coupled to the tool holder. The processor has programming that effects a desired movement of the end effector by transmitting drive signals to the tool drive motors of the manipulator. The processor reconfigures the program for the different joint geometries based on the tool-type signals.
In another aspect, the invention provides a robotic surgical system comprising a surgical tool having a surgical end effector and an interface. A manipulator assembly has a base and a tool holder for releasably engaging the interface. A plurality of tool engagement sensors are coupled to the tool holder. Each tool sensor produces a signal when the interface engages the holder. A processor is coupled to the tool engagement sensors. The processor has a tool change mode and a tissue manipulation mode. The processor requires tool signals from each of the sensors before changing the tool change mode to the tissue manipulation mode. The processor remains in the tissue manipulation mode when at least one, but not all, of the tool signals is lost.
The tools used in robotic surgery will be subjected to significant structural stress during use. The stress may result in temporary loss of an engagement signal from an engagement sensor. By providing at least two, and preferably three engagement sensors, the surgical procedure can continue safely with the loss of an engagement signal from an individual sensor so long as the system can still verify proper engagement between the manipulator and tool. This arrangement results in a robust tool engagement sensing system that avoids frequent delays during the surgical procedure as might occur from the loss of an individual signal.
In yet another aspect, the invention provides a robotic surgical system comprising a manipulator assembly having a base and tool holder which moves relative to the base. The tool holder has a plurality of drive elements. A sterile drape covers at least a portion of the manipulator. A sterile tool has a proximal interface and distal end effector. The distal end effector has a plurality of degrees of motion relative to the proximal interface. The degrees of motion are coupled to drive elements of the interface. An adapter is disposed adjacent the sterile drape between the holder and the interface. The adapter comprises a plurality of movable bodies. Each movable body has a first surface driven by the drive elements of the holder, and a second surface driving the driven elements of the tool.
In yet another aspect, the invention provides a robotic surgical tool for use with a robotic manipulator having a tool holder. The tool holder has magnetically actuatable circuitry. The tool comprises a probe having a proximal end and a distal end. A surgical end effector is disposed adjacent the distal end of the probe. An interface adjacent the proximal end of the probe is releasably coupleable with the holder. The interface comprises a magnet positioned so as to actuate the circuitry of the holder.